Weighing apparatus comprising a product transport surface comprising grooves

ABSTRACT

A weighing apparatus is described having a product transport surface ( 24 ) for transporting products thereon in a transporting direction ( 26 ). The product transport surface ( 24 ) has a plurality of grooves ( 28 ) which extend substantially parallel to each other and transversely to the transporting direction ( 26 ). In a cross section along the transporting direction ( 26 ), the upward sloping edges ( 32 ) and the downward sloping edges ( 30 ) of the grooves ( 28 ) form a saw tooth profile, wherein, when viewed in the transporting direction ( 26 ), each transition from the upward sloping edge ( 32 ) to the downward sloping edge ( 30 ) of two adjacent grooves ( 28 ) is sharp-edged. The product transport surface is particularly adapted for the transport of products having a soft, flexible and/or sticky surface. Also described are product transporting members in a weighing apparatus which are provided with such a product transport surface.

The present invention relates to a weighing apparatus comprising aproduct transport surface.

Further, a product transporting member in a weighing apparatus fortransporting a product to be weighed and/or for transporting a weighedproduct, a manufacturing process for a product transport surface and theuse of such a product transport surface in a weighing apparatus aredisclosed.

When products are transported by fixed or moving transporting members,adhesive forces and frictional forces occur at the contact area of theproduct transporting members and the surface of the products. Fortransporting a product along a transporting direction, the transportingmembers are, for example, slanted such that the product is moved bygravitational force. Further, the product may be moved on a transportingmember by vibration of said transporting member, for example byattaching the transport member to a vibration motor.

Depending on the consistency and surface texture of the transportedproduct, different adhesive and frictional forces occur. In particular,when products having a soft and flexible surface are transported, theproduct surface snuggles against the transport surface of the transportmember. In such cases, there are large contact areas between the productand the transporting member which leads to high adhesive and frictionalforces. Accordingly, part of the product remains stuck on the transportsurface which makes a continuous and smooth transport of the productimpossible.

In particular, such problems occur when transporting products having asoft, flexible and/or sticky surface in a weighing apparatus. In such aweighing apparatus, the products to be weighed must be transported tothe weighing receptacle and after the weighing operation, the productsmust be transported to an outlet which leads, for example, into apackaging machine. Products to be weighed with such a weighing apparatusare typically food stuffs or pharmaceutical products. In the food sectorand pharmaceutical sector, the products to be weighed often have a soft,flexible and/or sticky surface. In the food sector, products having asoft, flexible and sticky surface are, for example, pieces of meat,pieces of fruits, leafs of salad, etc. Typically, a combinatorialweighing apparatus is employed as a weighing apparatus for the productsin the food and pharmaceutical sector.

In conventional weighing apparatuses, transporting members having astructured surface have been employed in order to achieve a smooth andcontinuous transport of the products. These conventional structures hadcontinuous and smooth contours. However, with such conventionalstructures, the problem occurs that in case of products having a soft,flexible and/or sticky surface, a smooth and continuous transport ofsuch products can not be achieved. The products rather stick to suchproduct transport surfaces having the smooth and continuous contours.

Accordingly, it is an object of the present invention to provide aweighing apparatus comprising a product transport surface which allows acontinuous and smooth transport of products having a soft, flexibleand/or sticky surface. In particular, a continuous and smooth transportof products of the food and pharmaceutical sector shall be achieved in aweighing apparatus.

The object is solved by a weighing apparatus comprising a producttransport surface according to claim 1. Further preferred embodiments ofthe present invention are subject-matter of the sub-claims. Inparticular, the present invention also relates to a product transportingmember according to claim 12 and to a manufacturing process of a producttransport surface according to claim 13.

According to the present invention, the product transport surfacecomprises a plurality of grooves which extend substantially parallel toeach other. In a cross section taken along the transporting directionwhich extends in an angle to the extension direction of the grooves, theupward and downward sloping edges of the grooves form a saw toothprofile. Further, when viewed in the transporting direction, eachtransition from the upward sloping edge to the downward sloping edge oftwo adjacent grooves is sharp-edged.

In this present application, with “upward sloping edge”, reference ismade to the edge or face of each groove which extends, when viewed inthe transporting direction, upward towards the product to betransported. Conversely, with “downward sloping edge”, reference is madeto the edge or face of each groove which extends, when viewed in thetransporting direction, downwards away from the product to betransported.

In the product transport surface as defined above, a ridge is formedbetween two adjacent grooves. The ridge has a top edge extendingtransversely to the transporting direction and being sharp-edged.Accordingly, the plurality of grooves as described above form aplurality of ridges each having a sharp edge at the top thereof.

When the product is transported on such a product transport surface in atransporting direction, the contact area between the product and theproduct transport surface is restricted to the top edges of theplurality of ridges and thus, the contact area is small. Accordingly,the adhesive and frictional forces are low. Further, as the transportingdirection is arranged transversely to the extension direction of thegrooves, it is avoided that the ridges cut into the product while theproduct is transported. In case that the product transport surface isvibrated, for example by a vibration motor, the impact forces can beeffectively transmitted to the product via the sharp-edged top edges ofthe plurality of ridges. By the provision of the sharp-edged transition,adherence of product parts or contamination is avoided and thus,contamination of the product transport surface is reduced. Further, ithas been observed that by the provision of such a sharp-edgedtransition, the transported products pick up product parts orcontamination sticking on the product transport surface more effectivelyand thus, the self-cleaning effect is enhanced.

By the provision of the sharp-edged transition, the product is only incontact with the upper part of the plurality of ridges. It is therebyavoided that the product surface of the products snuggles downward alongthe faces or edges of the grooves. Accordingly, even when transportingsoft products, atmospheric pressure is maintained in the bottom of thegrooves. Thus, the occurrence of negative pressure when the product islifted upwards and moved forward—e.g. by vibration of the producttransport surface—is avoided. In particular, when the product is liftedupwards and moved forward any negative pressure can instantly becompensated by an airflow along the grooves beneath the product to betransported. Thus, a continuous and smooth transport of the product canbe achieved.

According to a further embodiment of the present invention, it isprovided that, when viewed in the transporting direction, theinclination angle of the upward sloping edges differs from theinclination angle of the downward sloping edges. The “inclination angle”of the upward sloping edge is hereby defined as the angle between theupward sloping edge and the plane formed by the product transportsurface. Accordingly, also the “inclination angle” of the downwardsloping edge is defined as the angle formed between the downward slopingedge and the plane formed by the product transport surface.

According to a preferred embodiment of the present invention, theinclination angle of the upward sloping edges is smaller than theinclination angle of the downward sloping edges. By the provision ofsuch an asymmetric profile, the angle of the face directed to thetransporting direction of each ridge with regard to the product surfaceis preferable. Thus, an effective transmission of the impact forces canbe achieved when the product transport surface is vibrated. Further, asthe upward sloping edge of each ridge is inclined gently in thetransporting direction, a gentle transport of the product can beachieved. Accordingly, the danger of damaging the product is minimized.

According to a further embodiment of the present invention, the groovesextend substantially perpendicular to the transporting direction. Undersubstantially perpendicular, a range of 90°±5° is understood. Asmentioned above, in such an arrangement it is avoided that thesharp-edged ridges formed between the grooves cut deeply into theproducts. Thus, a smooth transport can be achieved and the danger ofdamaging the products can be minimized.

According to a further embodiment of the present invention, when viewedin the transporting direction, the transition from the downward slopingedge to the upward sloping edge of each groove is sharp-edged. By theprovision of such a sharp-edged bottom of each groove, it is furtheravoided that the product surface of the products snuggles downward tothe bottom of the grooves. Accordingly, the occurrence of negativepressure when the product is lifted upwards and moved forward—e.g. byvibration of the product transport surface—is further avoided, as isdiscussed above with regard to claim 1. In particular, when the productis lifted upwards and moved forward, any negative pressure can instantlybe compensated by an airflow along the grooves beneath the products tobe transported.

The material of the product transport surface depends on the product tobe transported. Preferred materials are metal, in particular steel, or asynthetic material, in particular PE (polyethylene), PVC (polyvinylchloride), PTFE (polytetrafluoro-ethylene) or POM (polyoxymethylene).

Also the dimensions of the grooves depend on the product to betransported. However, in weighing apparatuses in the food andpharmaceutical sector, the following dimensions are preferable:

For the width of each groove, i.e. the distance between two transitionsfrom the upward sloping edge to the downward sloping edge of adjacentgrooves, a range of 1-20 mm is suitable, and a range of 2-10 mm ispreferable. The width of each groove corresponds, at the same time, tothe distance between the top edges of two adjacent ridges.

Further, for the depth of each groove, i.e. the distance from the bottomof each groove to the top of the adjacent ridge, a range of 0.2-10 mm issuitable, and a range of 0.4-5 mm is preferable.

For the angle between each downward sloping edge and an adjacent upwardsloping edge, a range of 45°-135° is suitable, and a range of 70°-110°is preferable. This angle corresponds, at the same time, to the angleformed between each upward sloping edge and an adjacent downward slopingedge, when viewed in the transporting direction.

According to a further preferred embodiment of the present invention,each upward sloping edge is formed of a first upward sloping edge and asecond intermediate edge. The first upward sloping edge is arrangedafter the preceding downward sloping edge, when viewed in thetransporting direction. The second intermediate edge is arranged betweeneach first upward sloping edge and the following downward sloping edge,when viewed in the transporting direction. The inclination angle of thesecond intermediate edge differs from the inclination angle of the firstupward sloping edge, wherein the inclination angle is defined asmentioned above. By the provision of such a second intermediate edge,the product contact surface is slightly enlarged. However, thesharp-edged transition (here: between the second intermediate edge ofthe upward sloping edge and the downward sloping edge) according to thepresent invention is still maintained. By the provision of such anintermediate edge, a more gentle transport of the product can beachieved.

Such a profile comprising the second intermediate edge is, for example,preferable as a product transport surface of a conveyor trough of acombinatorial weighing apparatus, as will be discussed with reference tothe figures below.

According to a further embodiment, each second intermediate edge issloping upward when viewed in the transporting direction, wherein theinclination angle of the second intermediate edge is smaller than theinclination angle of the first upward sloping edge. According to afurther embodiment, each intermediate edge is substantially parallel tothe plane formed by the product transport surface. Under substantiallyparallel, an inclination angle of the second intermediate edge withregard to the plane formed by the product-transport surface in the rangeof 0°±5° is understood.

As is discussed above, the dimensions of the profile of the groovesdepend on the product to be transported. However, for a producttransport surface in weighing apparatuses for the transport of productsin the food and/or pharmaceutical sector, the following dimensions arepreferable:

For the width of each groove (as defined above) a range of 1-30 mm issuitable and a range of 2-15 mm is preferable. Further, for a width ofthe second intermediate edge along the transporting direction, a rangeof 0.2-10 mm is suitable, while a range of 0.3-5 mm is preferable.

Further, for a first height of the first upward sloping edge with regardto the bottom of the grooves, a range of 0.2-10 mm is suitable, while arange of 0.4-5 mm is preferable.

For a second height of the second intermediate edge with regard to thebottom of the grooves, a range of 0.2-10 mm is suitable, and a range of0.4-5 mm is preferable. With regard to the first and the second height,it is to be mentioned that this height is dimensioned in a directionperpendicular to the plane formed by the product transport surface, asis also obvious from the figures.

Further, for an angle formed between each downward sloping edge and anadjacent first upward sloping edge, a range of 45°-135° is suitable,while a range of 70°-110° is preferable.

According to a further embodiment, the surface of a product transportingmember for transporting a product to be weighed and/or for transportinga weighed product in a weighing apparatus, in particular in acombinatorial weighing apparatus, is formed as a product transportsurface as defined above. In particular, such a product transportingmember is a transport conveyor, a central dispersing device, a conveyortrough, a flap of a supply container or a weighing container fordischarging product from the respective container, or a hopper of acombinatorial weighing apparatus. In such a product transporting member,the advantages as discussed above with regard to the product transportsurface are achieved.

According to a further embodiment, also a manufacturing process of aproduct transport surface as defined above is provided. According tothis manufacturing process, the grooves are formed by milling, byembossing or by rolling a sheet or plate of raw material, or, in case ofa synthetic material, by an injection-moulding process such that, whenviewed in the transporting direction, each transition from the upwardsloping edge to the downward sloping edge of two adjacent grooves issharp-edged.

Further features and advantages of the invention are obvious from thedescription of embodiments on the basis of the enclosed drawings. Thefigures show:

FIG. 1 a schematic cross-sectional view of a combinatorial weighingapparatus;

FIG. 2 a schematic cross-sectional view along the transporting directionof a product transport surface according to a first embodiment of thepresent invention;

FIG. 3 a schematic cross-sectional view along the transporting directionof a product transport surface according to a second embodiment of thepresent invention;

FIG. 4 a side view of a flap of a supply container or of a weighingcontainer, the flap being provided with a product transport surfaceaccording to the first embodiment of the present invention;

FIG. 5 a front view of the flap shown in FIG. 4;

FIG. 6 a front view of a conveyor trough;

FIG. 7 a schematic cross-sectional view of the profile of the producttransport surface of the conveyor trough shown in FIG. 6; and

FIG. 8 a top view on the conveyor trough shown in FIG. 6.

In FIG. 1, a combinatorial weighing apparatus 2 is shown. In thefollowing, the product transporting members having surfaces which are incontact with the product to be weighed and with the weighed product willbe explained below. The product is delivered from a transport conveyor 4onto a central dispersing device 6 having a dispensing edge 8 aroundwhich a plurality of conveyor troughs 10 is arranged. Each of theseconveyor troughs 10 is connected to a vibration motor 12. Below an endof each conveyor trough 10, which end is facing away from the dispersingdevice 6, a supply container 14 is arranged. Below each supply container14, a weighing container 16 is positioned.

Each of the supply containers 14 and the weighing containers 16comprises two flaps 18 which are arranged opposite to each other andwhich can be opened for discharging the product from the respectivecontainer 14, 16. Each of the flaps 18 is attached to the respectivecontainer 14, 16 by a hinge mechanism. The opening and closing of therespective flaps 18 is controlled by a central control unit (not shown)of the combinatorial weighing apparatus. The product discharged from theweighing containers 16 is received in a hopper 20 arranged below theplurality of weighing containers 16. The discharge opening 22 of thehopper 20 discharges the weighed product. The weighed product is, forexample, discharged into a packaging machine (not shown).

Accordingly, the product to be weighed is transported by the transportconveyor 4 to the central dispersing device 6, afterwards it isdispensed onto the plurality of conveyor troughs 10. From the outer endof each conveyor trough 10, the product to be weighed is delivered intothe supply container 14. By opening the flaps 18 of the supply container14, the product is discharged into the weighing container 16, whereinthe product is weighed. Afterwards, the flaps 18 of the correspondingweighing containers 16 are opened according to a control signal of thecentral control unit (not shown) of the combinatorial weighing apparatus2. Accordingly, the weighed product is received in the hopper 20 anddischarged through the discharge opening 22 of the hopper 20.

As is obvious from the description above, each of the transport conveyor4, the central dispersing device 6, the conveyor troughs 10, the supplycontainers 14, the weighing containers 16, the flaps 18 and the hopper20 comprise surfaces which are in contact with the transported product.Accordingly, when products having a soft and/or flexible and/or stickysurface are to be weighed in such a combinatorial weighing apparatus 2,some or each of the surfaces of the product transporting membersmentioned above are preferably formed as a product transport surfaceaccording to the present invention.

In FIG. 2, a schematic cross section of a product transport surface 24according to a first embodiment of the present invention is shown. Thecross section is taken along the transporting direction 26. As mentionedabove, the product transport surface 24 is formed of a plurality ofgrooves 28 extending substantially perpendicular to the transportingdirection 26. Each groove is formed by a downward sloping edge 30 and anupward sloping edge 32. The upward sloping edge 32 and the downwardsloping edge 30 of two adjacent grooves 28 form a ridge 34.

When viewed in the transporting direction 26, each transition 36 fromthe upward sloping edge 32 to the downward sloping edge 30 issharp-edged. Accordingly, each ridge 34 comprises a sharp-edged edge 36extending perpendicular to the transporting direction 26 and to theplane shown in FIG. 2.

Further, as is obvious from FIG. 2, when viewed in the transportingdirection 26, the inclination angle α of the upward sloping edges 32 issmaller than the inclination angle β of the downward sloping edges 30.As is obvious from FIG. 2, the inclination angles α and β are defined bythe angle between the upward and downward sloping edges 32 and 30,respectively, and the plane 46 formed by the product transport surface.

For convenience of description and illustration, in FIGS. 2 and 3, the“plane formed by the product transport surface” is shown as the plane 46connecting the base edges, i.e. the lower transitions 38 of theplurality of grooves 28 of the product transport surface 24, 40.However, the “plane formed by the product transport surface” mayalternatively be shown as a plane connecting the top edges, i.e. theupper transitions 36, of the plurality of ridges 34. Such alternativeupper plane would be parallel to the plane 46, as is obvious from FIGS.2 and 3. Accordingly, the level of the plane has no influence on thedefinition of the inclination angle.

Further, as is obvious from FIG. 2, when viewed in the transportingdirection 26, also the transition 38 from the downward sloping edge 30to the upward sloping edge 32 of each groove 28 is sharp-edged.

Experiments of the applicants have revealed that sharp-edged transitions36 and 38 can in particular be achieved by milling the grooves 28 into asteel plate. However, further manufacturing processes and materials arepossible to obtain such sharp-edged transitions 36 and 38, as isdiscussed above.

Preferably, the width L of each groove 28, i.e. the distance between twotransitions 36 from the upward sloping edge 32 to the downward slopingedge 30 of adjacent grooves 28, is in the range of 1-20 mm, preferablyin the range of 2-10 mm. As is obvious from FIGS. 2 and 3, the distancebetween the two transitions 36 corresponds, at the same time, to thedistance between two transitions 38 from the downward sloping edge 30 tothe upward sloping edge 32, 32′ of each groove 28. Further, the depth Hof each groove is in the range of 0.2-10 mm, preferably in the range of0.4-5 mm. Further, an angle γ between each downward sloping edge 30 andan adjacent upward sloping edge 32 is in the range of 45°-135°,preferably in the range of 70°-110°. This angle γ corresponds to theangle γ′ which is formed between each upward sloping edge 32 and anadjacent downward sloping edge 30, when viewed in the transportingdirection 26.

In FIG. 3, a cross section along a product transporting direction 26 ofa product transport surface 40 according to a second embodiment of thepresent invention is shown. The same reference numbers are used forthose parts which are identical to the first embodiment shown in FIG. 2.In the following, only the differences with regard to the firstembodiment are explained.

In the product transport surface 40, each upward sloping edge 32′ isformed of a first upward sloping edge 42 and a second intermediate edge44. When viewed in the transporting direction 26, the first upwardsloping edge 42 is arranged after the preceding downward sloping edge30, and the second intermediate edge 44 is arranged between each firstupward sloping edge 42 and the following downward sloping edge 30.

As is obvious from FIG. 3, the inclination angle of the secondintermediate edge 44 differs from the inclination angle α of the firstupward sloping edge 42. In particular, in the embodiment shown in FIG.3, the second intermediate edge 44 is substantially parallel to theplane 46 (as defined above).

In the second embodiment, the width L (as defined above) of each groove28 is in the range of 1-30 mm, preferably in the range of 2-15 mm. Thewidth L₂ of the second intermediate edge 44 along the transportingdirection 26 is in the range of 0.2-10 mm, preferably in the range of0.3-5 mm. A first height H′ of the first upward sloping edge 42 withregard to the bottom 38 of the grooves 28 is in the range of 0.2-10 mm,preferably in the range of 0.4-5 mm. A second height H of the secondintermediate edge 44 with regard to the bottom 38 of the grooves 28 isin the range of 0.2-10 mm, preferably in the range of 0.4-5 mm. Thesecond height H is, at the same time, the height H of the upward slopingedge 32′. The angle γ between each downward sloping edge 30 and anadjacent first upward sloping edge 42 is in the range of 45°-135°,preferably in the range of 70°-110°.

In FIGS. 4 and 5, a flap 18 for closing and opening a supply container14 or a weighing container 16 of a weighing apparatus is shown. The flap18 comprises a lever 47 which is connected to a control arm (not shown)for opening and closing the flap 18. The flap 18 further comprisessuspension members 48 by which the flap 18 is attached pivotably to therespective supply container 14 or weighing container 16. The flapsurface 50 which is arranged on the inner side of the respective supplycontainer 14 or weighing container 16 is provided with a producttransport surface 24 according to the first embodiment of the presentinvention.

As is obvious from FIG. 4, the respective grooves 28 are extendingsubstantially perpendicular to the transporting direction 26 along whichthe product is transported when the flap 18 is opened to discharge theproduct from the respective container 14, 16.

In FIGS. 6 and 8, a conveyor trough 10 according to the presentinvention is shown. In the perspective schematic view of FIG. 6, onlythe geometrical form of the conveyor trough 10 is shown. The producttransport surface 40 provided on the upper surface of the trough 10 isshown in FIG. 8. In FIG. 7, a cross-sectional view along thetransporting direction 26 is shown.

As is obvious from FIG. 6, the conveyor trough 10 comprises a centralgroove 52 directing the product to be weighed in a transportingdirection 26 towards an opening 54 of the trough 10. On both sides ofthe groove 52, upward sloping side walls 56, 58 are provided such thatthe product is directed to the central groove 52.

On the side opposite to the groove 52, an upstanding outer wall 60extends along the opening 54. The upstanding outer wall 60 is alsoarranged along the outer edges of the side walls 56 and 58.

As shown in FIG. 8, the plurality of grooves 28 extends perpendicular tothe transporting direction 26. As shown in the cross-sectional view ofFIG. 7, the product transport surface 40 is formed according to thesecond embodiment of the present invention, as is also shown in FIG. 3.

As is schematically shown in FIG. 6, the conveyor trough 10 is curved inthe direction perpendicular to the transporting direction 26. However,the grooves 28 extend along the curved surface, which is onlyschematically shown in FIG. 8.

This invention is not limited to the embodiments shown in the Figures.In particular, the product transport surfaces can also be provided inother types of weighing apparatuses. Further, the product transportsurfaces can be provided on further transporting members of suchweighing apparatuses. Such product transport surfaces can also beprovided in a packaging machine for transporting the weighed product.

The flap 18 shown in FIGS. 4 und 5 has a profile according to the firstembodiment of the present invention, while the conveyor trough 10 shownin FIG. 6 to 8 has a profile according to the second embodiment of thepresent invention. Conversely, the flap 18 can, of course, also beprovided with a product transport surface 40 according to the secondembodiment of the present invention, and the conveyor trough 10 can alsobe provided with a product transport surface 24 according to the firstembodiment of the present invention.

As is already discussed with regard to FIG. 6 to 8, the producttransport may be curved and the plurality of grooves extends along thecurved surface.

The invention claimed is:
 1. A weighing apparatus comprising a producttransport surface for transporting products thereon in a transportingdirection, the product transport surface comprising: a plurality ofgrooves extending substantially parallel to each other and transverselyto the transporting direction, wherein in a cross section along thetransporting direction, upward and downward sloping edges forming thegrooves form a saw tooth profile, wherein, when viewed in thetransporting direction, each transition from the upward sloping edge tothe downward sloping edge of two adjacent grooves is sharp-edged, andeach upward sloping edge is formed by a first upward sloping edge whichis arranged after the preceding downward sloping edge when viewed in thetransporting direction, and a second intermediate edge arranged betweenthe first upward sloping edge and the following downward sloping edgewhen viewed in the transporting direction, wherein the inclination angleof the second intermediate edge differs from the inclination angle (α)of the first upward sloping edge, wherein the angle between eachdownward sloping edge and an adjacent upward sloping edge is in therange of 70°-110°.
 2. The weighing apparatus according to claim 1,wherein, when viewed in the transporting direction, the inclinationangle (α) of the upward sloping edges differs from the inclination angle(β) of the downward sloping edges.
 3. The weighing apparatus accordingto claim 2, wherein, when viewed in the transporting direction, theinclination angle (α) of the upward sloping edges is smaller than theinclination angle (β) of the downward sloping edges.
 4. The weighingapparatus according to claim 1, wherein the grooves extend substantiallyperpendicular to the transporting direction.
 5. The weighing apparatusaccording to claim 1, wherein, when viewed in the transportingdirection, a transition from the downward sloping edge to the upwardsloping edge of each groove is sharp-edged.
 6. The weighing apparatusaccording to claim 1, wherein the product transport surface comprises ametal or a synthetic material.
 7. The weighing apparatus according toclaim 6, wherein the metal is steel.
 8. The weighing apparatus accordingto claim 6, wherein the synthetic material is selected from the groupconsisting of PE, PVC, PTFE and POM.
 9. The weighing apparatus accordingto claim 1, wherein each second intermediate edge is sloping upward whenviewed in the transporting direction and the inclination angle of thesecond intermediate edge is smaller than the inclination angle (α) ofthe first upward sloping edge.
 10. The weighing apparatus according toclaim 1, wherein each second intermediate edge is substantially parallelto the plane formed by the product transport surface.
 11. A weighingapparatus comprising a product transporting member for transporting aproduct to be weighed and/or for transporting a weighed product, theapparatus comprising a transport conveyor, a central dispersing device,a conveyor trough, a flap of a supply container or of a weighingcontainer for discharging product from the respective container, or ahopper of a combinatorial weighing apparatus, wherein the surface of theproduct transporting member which gets into contact with the product tobe transported is formed as a product transport surface according toclaim
 1. 12. A weighing apparatus comprising a central dispersing devicehaving a dispersing edge around which a plurality of conveyor troughs isdisposed, wherein a supply container is located at an end of eachconveyor trough that faces away form the dispersing device, and aweighing container is positioned below each supply container, wherein atleast one of the dispersing device, conveyor trough, the supplycontainer and the weighing container comprises a product transportsurface for transporting products thereon in a transporting direction,the product transport surface comprising: a plurality of grooves eachextending substantially across an entire transport surface, andsubstantially parallel to each other and transversely to thetransporting direction, wherein, in a cross section along thetransporting direction, upward and downward sloping edges forming thegrooves form a saw tooth profile, wherein, when viewed in thetransporting direction, each transition from the upward sloping edge tothe downward sloping edge of two adjacent grooves is sharp-edged. 13.The weighing apparatus of claim 12, wherein each upward sloping edge isformed by: a first upward sloping edge which is arranged after thepreceding downward sloping edge when viewed in the transportingdirection, and a second intermediate edge, following the first upwardsloping edge, arranged substantially parallel to a plane made by theproduct transport surface, the plane defined by connecting base edges ofthe plurality of grooves.
 14. The weighing apparatus of claim 13,further comprising an angle (γ) between each downward sloping edge andan adjacent upward sloping edge, wherein the angle (γ) is in the rangeof 70° to 110°.
 15. The weighing apparatus of claim 12, wherein thesupply container and the weighing container comprise a flap for openingand closing the container, at least one the flap having said producttransport surface.
 16. The weighing apparatus of claim 12, wherein eachupward sloping edge is formed by: a first upward sloping edge, which isarranged after the preceding downward sloping edge when viewed in thetransporting direction, having a first inclination angle, and a secondintermediate edge, following the first upward sloping edge, having asecond inclination angle, wherein the second inclination angle issmaller than the first inclination angle.
 17. The weighing apparatus ofclaim 16, further comprising an angle (γ) between each downward slopingedge and an adjacent upward sloping edge, wherein the angle (γ) is inthe range of 70° to 110°.